Lab requisitions under Dr. Latsky

A one-page website that prepares the Ontario Ministry of Health Laboratory Requisition, form 4422-84 (2026/04), printed under:

Dr. Jason Latsky · 2896 Dundas Street W, Toronto ON M6P 1Y8 Billing 052360 · CPSO 143244

It is for an allied provider to fill in the patient and the tests, print the form, and have Dr. Latsky sign it. It is not an EMR: nothing is stored, no patient list, no login. The page sends one order, gets one PDF back, and that is all.

What it does

1. Patient — name as on the health card, date of birth, sex, health number and version code, address, phone, payer (OHIP / uninsured / WSIB).
2. Tests — every tick box on the form, grouped as printed (Biochemistry, Hematology, Immunology, Microbiology, Viral Hepatitis, PSA), the vitamin D insured / uninsured choice, and the eleven "Other Tests" free-text lines with quick-add chips for common tests. A twelfth line prints a second sheet.
3. Clinical information, date of service, the date beside the signature, and an optional "copy of results to" block so the lab also sends the report to the provider.
4. Print — the ministry's own PDF, filled and flattened, previewed on the page with Print / Download / Open buttons.

The form's own rules are enforced before anything prints: glucose needs Random or Fasting; a hepatitis box needs Acute, Chronic or Immune status; PSA needs Insured or Uninsured; Chlamydia, GC, Wound and Other Swabs need a specimen source.

The signature box is always left empty. The PDF is unsigned; Dr. Latsky signs by hand after review.

Running it

npm install
npm start          # http://localhost:3000
npm run verify     # form map vs. the ministry PDF, builder rules, end-to-end fill
npm run demo       # writes out/demo.pdf

Node 18 or newer. One dependency, @cantoo/pdf-lib, which opens the ministry's encrypted-with-an-empty-password form.

On Vercel

The repo deploys as-is: public/ is static and api/requisition.js is a serverless function (vercel.json makes sure the PDF ships with it).

Changing the clinician block

config.js, or environment variables CLINICIAN_NAME, CLINICIAN_ADDRESS, CLINICIAN_BILLING, CLINICIAN_CPSO, CLINICIAN_PHONE (urgent contact number, blank by default). The browser cannot change it.

Layout

public/index.html      the page
api/requisition.js     GET: form description · POST: the filled PDF
config.js              who it prints under
lib/form-map.js        ministry PDF field names ↔ clinical meaning (ground truth)
lib/build.js           ticked boxes + lines → plan, with the form's rules
lib/fill.js            plan → filled, flattened PDF (one page per sheet)
lib/acroform.js        load the encrypted blank, set states, flatten
lib/forms/on-4422-84.pdf   the ministry's file, byte-for-byte
scripts/verify-forms.mjs   every mapped field exists in the PDF
scripts/verify-build.mjs   builder rules and a two-sheet render

form-map.js, fill.js and acroform.js are copied from the Orilume MD EMR's lib/lab-requisition/ module. If the ministry reissues the form, re-derive the map there and copy it over; verify-forms.mjs fails until it matches.